Maslamah ibn Abd al-Malik

Maslamah ibn Abd al-Malik ibn Marwan (died 121 AH / 738 CE) was the most capable Umayyad military commander of the late Umayyad period, the prince-general who led the great siege of Constantinople in 98–99 AH / 716–718 CE and who directed major campaigns on both the Byzantine and Central Asian frontiers. He was a son of Caliph Abd al-Malik and the brother of Caliphs al-Walid, Sulayman, and Hisham.

His siege of Constantinople was the second major Islamic attempt to take the Byzantine capital and was on a massive scale — accounts speak of a besieging force of over 100,000 men and a large naval contingent. The siege lasted over a year and ultimately failed due to a combination of factors: Byzantine Greek fire that destroyed the Muslim fleet, a harsh winter, Bulgarian attacks on the besieging army from the rear, and the arrival of relief provisions to the city. The failure was one of the most significant strategic setbacks in Umayyad history.

He also conducted campaigns in the Caucasus, fighting the Khazars and the Byzantine client states in Armenia and Georgia. His northern campaigns extended Umayyad influence as far as possible in that direction, though the limits of sustainable expansion were becoming apparent.

He is also credited with spending time in Damascus engaged in religious practices and reportedly being influenced by the early Sufi teacher Hasan al-Basri through correspondence. He died in 121 AH and is remembered as the most militarily accomplished of the Umayyad princes who never became caliph — a function partly of his not having been designated heir and partly of the politics of succession among Abd al-Malik's many sons.